<template>
  <div>
    <div class="goods">
      <div class="menu-wrapper" ref="menuWrapper">
        <ul>
          <li
            v-for="(item, index) in goods"
            class="menu-item"
            :class="{ current: currentIndex === index }"
            @click="selectMenu(index, $event)"
            ref="menuList"
            :key="index"
          >
            <span class="text border-1px">
              <span
                v-show="item.type > 0"
                class="icon"
                :class="classMap[item.type]"
              ></span
              >{{ item.name }}
            </span>
          </li>
        </ul>
      </div>

      <div class="foods-wrapper" ref="foodsWrapper">
        <ul>
          <li
            v-for="(item, index) in goods"
            class="food-list"
            ref="foodList"
            :key="index"
          >
            <h1 class="title">{{ item.name }}</h1>
            <ul>
              <li
                @click="selectFood(food, $event)"
                v-for="(food, index) in item.foods"
                class="food-item border-1px"
                :key="index"
              >
                <div class="icon">
                  <img width="57" height="57" :src="food.icon" />
                </div>
                <div class="content">
                  <h2 class="name">{{ food.name }}</h2>
                  <p class="desc">{{ food.description }}</p>
                  <div class="extra">
                    <span class="count">月售{{ food.sellCount }}份</span
                    ><span>好评率{{ food.rating }}%</span>
                  </div>
                  <div class="price">
                    <span class="now">￥{{ food.price }}</span
                    ><span class="old" v-show="food.oldPrice"
                      >￥{{ food.oldPrice }}</span
                    >
                  </div>
                  <div class="cartcontrol-wrapper">
                    <cartcontrol @add="addFood" :food="food"></cartcontrol>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>

      <shopcart
        ref="shopcart"
        :selectFoods="selectFoods"
        :deliveryPrice="seller.deliveryPrice"
        :minPrice="seller.minPrice"
      ></shopcart>
    </div>
    <food @add="addFood" :food="selectedFood" ref="food"></food>
  </div>
</template>

<script>
import BScroll from 'better-scroll';
import { getGoods } from 'api';

import Cartcontrol from 'components/cartcontrol';
import Shopcart from 'components/shopcart';
import Food from 'components/food';

export default {
  name: 'Goods',
  props: {
    seller: {
      type: Object,
    },
  },
  components: {
    Cartcontrol,
    Shopcart,
    Food
  },
  data() {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0,
      selectedFood: {},
    };
  },
  created() {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee'];

    this._getGoods();
  },
  methods: {
    _getGoods() {
      getGoods().then((goods) => {
        this.goods = goods;
        this.$nextTick(() => {
          this._initScroll();
          this._calculateHeight();
        });
      });
    },
    _initScroll() {
      this.meunScroll = new BScroll(this.$refs.menuWrapper, {
        click: true,
      });

      this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
        click: true,
        probeType: 3,
      });

      this.foodsScroll.on('scroll', (pos) => {
        // 判断滑动方向，避免下拉时分类高亮错误（如第一分类商品数量为1时，下拉使得第二分类高亮）
        if (pos.y <= 0) {
          this.scrollY = Math.abs(Math.round(pos.y));
        }
      });
    },
    _calculateHeight() {
      let foodList = this.$refs.foodList;
      let height = 0;
      this.listHeight.push(height);
      for (let i = 0; i < foodList.length; i++) {
        let item = foodList[i];
        height += item.clientHeight;
        this.listHeight.push(height);
      }
    },
    _followScroll(index) {
      let menuList = this.$refs.menuList;
      let el = menuList[index];
      this.meunScroll.scrollToElement(el, 300, 0, -100);
    },

    selectMenu(index, event) {
      if (!event._constructed) {
        return;
      }
      let foodList = this.$refs.foodList;
      let el = foodList[index];
      this.foodsScroll.scrollToElement(el, 300);
    },
    selectFood(food, event) {
      if (!event._constructed) {
        return;
      }
      this.selectedFood = food;
      this.$refs.food.show();
    },
    addFood(target) {
      this._drop(target);
    },
    _drop(target) {
      // 体验优化,异步执行下落动画
      this.$nextTick(() => {
        this.$refs.shopcart.drop(target);
      });
    },
  },
  computed: {
    currentIndex() {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i];
        let height2 = this.listHeight[i + 1];
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          this._followScroll(i);
          return i;
        }
      }
      return 0;
    },
    selectFoods() {
      let foods = [];
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if (food.count) {
            foods.push(food);
          }
        });
      });

      return foods;
    },
  },
};
</script>

<style lang="stylus" rel="stylesheet/stylus">
@import "~assets/stylus/mixin.styl"

.goods
  display: flex
  position: absolute
  top: 174px
  bottom: 46px
  width: 100%
  overflow: hidden
  .menu-wrapper
    flex: 0 0 80px
    width: 80px
    background: #f3f5f7
    .menu-item
      display: table
      height: 54px
      width: 56px
      padding: 0 12px
      line-height: 14px
      &.current
        position: relative
        z-index: 10
        margin-top: -1px
        background: #fff
        font-weight: 700
        .text
          border-none()
      .icon
        display: inline-block
        vertical-align: top
        width: 12px
        height: 12px
        margin-right: 2px
        background-size: 12px 12px
        background-repeat: no-repeat
        &.decrease
          bg-image('goods','decrease_3')
        &.discount
          bg-image('goods','discount_3')
        &.guarantee
          bg-image('goods','guarantee_3')
        &.invoice
          bg-image('goods','invoice_3')
        &.special
          bg-image('goods','special_3')
      .text
        display: table-cell
        width: 56px
        vertical-align: middle
        border-1px(rgba(7, 17, 27, 0.1))
        font-size: 12px
  .foods-wrapper
    flex: 1
    .title
      padding-left: 14px
      height: 26px
      line-height: 26px
      border-left: 2px solid #d9dde1
      font-size: 12px
      color: rgb(147, 153, 159)
      background: #f3f5f7
    .food-item
      display: flex
      margin: 18px
      padding-bottom: 18px
      border-1px(rgba(7, 17, 27, 0.1))
      &:last-child
        border-none()
        margin-bottom: 0
      .icon
        flex: 0 0 57px
        margin-right: 10px
      .content
        flex: 1
        .name
          margin: 2px 0 8px 0
          height: 14px
          line-height: 14px
          font-size: 14px
          color: rgb(7, 17, 27)
        .desc, .extra
          line-height: 10px
          font-size: 10px
          color: rgb(147, 153, 159)
        .desc
          line-height: 12px
          margin-bottom: 8px
        .extra
          .count
            margin-right: 12px
        .price
          font-weight: 700
          line-height: 24px
          .now
            margin-right: 8px
            font-size: 14px
            color: rgb(240, 20, 20)
          .old
            text-decoration: line-through
            font-size: 10px
            color: rgb(147, 153, 159)
        .cartcontrol-wrapper
          position: absolute
          right: 0
          bottom: 12px
</style>
